1. Field
The present disclosure relates to a high pressure water electrolysis device.
2. Description of the Related Art
For example, hydrogen is used as fuel gas for power generation reaction in a fuel cell. In general, a water electrolysis device is used for producing hydrogen gas. The water electrolysis device uses a solid polymer electrolyte membrane in order to generate hydrogen (and oxygen) by electrolyzing water. Electrode catalyst layers are provided on both surfaces of a solid polymer electrolyte membrane so as to form an electrolyte membrane-electrode assembly, and power supplying bodies are disposed on both sides of the electrolyte membrane-electrode assembly so as to form a unit.
Multiple units are then stacked and a voltage is applied to both ends of the units in the stacking direction, and water is supplied to anode power supplying bodies. Accordingly, on the anode side of the electrolyte membrane-electrode assembly, water is electrolyzed to generate hydrogen ions (protons), which move to the cathode side through the solid polymer electrolyte membranes and combine with electrons, thereby producing hydrogen. On the other hand, on the anode side, oxygen generated along with hydrogen is discharged from the unit with excessive water.
As the water electrolysis device, a high pressure water electrolysis device is used that produces oxygen and hydrogen which is higher in pressure than the oxygen by electrolyzing water. In the device, there is a problem in that a solid polymer electrolyte membrane is pressed against the anode power supplying body due to a differential pressure between the anode side and the cathode side, and damage such as injury may occur in the solid polymer electrolyte membrane.
For example, there is known an electrolysis device which has been disclosed in Japanese Unexamined Patent Application Publication No. 2010-189708. In the electrolysis device, a protective sheet member, in which a great number of through holes are formed, is interposed between an electrolyte membrane and a power supplying body, and the through holes each have a tapered shape with a smaller diameter toward the electrolyte membrane. Thus, it is claimed that damage of the electrolyte membrane may be prevented as much as possible with a simple configuration, and improvement in water supply performance and gas release performance may be achieved.